Which movies are really "surprise hits"?

[Rzzzz]

1. 28 Days Later- earned $82.8 million on a £5 million budget.

2. Smokey and the Bandit- earned over $300 million on a $4.3 million budget.

"Just two days before production was to begin, Universal sent a "hatchet man" to Atlanta to inform Needham that the budget was being trimmed by $1 million. With Reynolds' salary at $1 million, Needham was left with only $3.3 million to make the film. Needham and assistant director David Hamburger spent 30 hours revising the shooting schedule."
It seems Universal didn't have much confidence in the film.

3. Bonnie and Clyde

"At first, Warner Bros. did not promote Bonnie and Clyde for general release, but mounted only limited regional releases that seemed to confirm its misgivings about the film's lack of commercial appeal". "Much to the surprise of Warner Bros.' management, the film became a major box-office success."

4. Boondock Saints- Budget $6 million.

"Boondock Saints became a cult classic through word of mouth and its home video release, ultimately grossing $50 million in sales."

5. Carrie (1976)- $33.8 million against its $1.8 million budget.